Different types of moveable barrier operators have been sold over the years and these systems have been used to actuate various types of moveable barriers. For example, garage door operators have been used to move garage doors and gate operators have been used to open and close gates.
Such barrier movement operators may include a wall control unit, which is connected to send signals to a head unit thereby causing the head unit to open and close the barrier. In addition, these operators often include a receiver unit at the head unit to receive wireless transmissions from a hand-held code transmitter or from a keypad transmitter, which may be affixed to the outside of the area closed by the barrier or other structure.
Movable barrier operator systems often include safety sensors or devices. These safety sensors are used to detect obstructions in the path of travel of the barrier to provide increased safety of operation. Previous systems are programmed to react differently when the safety sensors are not attached. In some of these systems, the sensors must be detected by the operator before travel of the barrier is allowed.
In some situations, both primary and secondary safety sensors are used. For example, a primary sensor may determine when to reverse movement of the barrier and a secondary safety sensor used to verify the accuracy of the reading of the primary safety sensor. In some instances, the use of a secondary safety sensor is required.
Different countries have different standards with regards to requiring the use of secondary safety sensors. For example, some European standards require that an operator and barrier combination be tested to determine the force impacted on a strain gage that would cause a reversal of the movement of the barrier. If the force exceeds a threshold, then a secondary safety sensor is required to be installed. Unfortunately, using this approach, testing is required upon potentially every installation of a barrier operator. Since a test may need to be performed upon every installation, product cost, delays, and user frustration increase.